From d89866dd74044a1ac19f515a4795972a1369ebb0 Mon Sep 17 00:00:00 2001
From: Calvin Combs <comcalvi@amazon.com>
Date: Mon, 8 Jan 2024 14:03:31 -0800
Subject: [PATCH] reset point, in case I break it all...

---
 .../cloudformation-diff/lib/diff-template.ts    | 17 ++++++++++++++---
 .../cloudformation-diff/lib/diff/types.ts       |  2 +-
 .../aws-cdk/lib/api/nested-stack-helpers.ts     |  9 +--------
 packages/aws-cdk/lib/cdk-toolkit.ts             |  1 -
 4 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/packages/@aws-cdk/cloudformation-diff/lib/diff-template.ts b/packages/@aws-cdk/cloudformation-diff/lib/diff-template.ts
index 055bc3be8248b..98cbb25408705 100644
--- a/packages/@aws-cdk/cloudformation-diff/lib/diff-template.ts
+++ b/packages/@aws-cdk/cloudformation-diff/lib/diff-template.ts
@@ -11,6 +11,14 @@ export * from './diff/types';
 type DiffHandler = (diff: types.ITemplateDiff, oldValue: any, newValue: any) => void;
 type HandlerRegistry = { [section: string]: DiffHandler };
 
+export type NestedChangeSet = CloudFormation.DescribeChangeSetOutput & {
+  Changes?: CloudFormation.Changes & {
+    ResourceChange?: {
+      NestedChanges?: CloudFormation.DescribeChangeSetOutput | NestedChangeSet,
+    },
+  }[],
+};
+
 const DIFF_HANDLERS: HandlerRegistry = {
   AWSTemplateFormatVersion: (diff, oldValue, newValue) =>
     diff.awsTemplateFormatVersion = impl.diffAttribute(oldValue, newValue),
@@ -209,7 +217,7 @@ function deepCopy(x: any): any {
   return x;
 }
 
-function filterFalsePositivies(diff: types.TemplateDiff, changeSet: CloudFormation.DescribeChangeSetOutput) {
+function filterFalsePositivies(diff: types.TemplateDiff, changeSet: CloudFormation.DescribeChangeSetOutput | NestedChangeSet) {
   const replacements = findResourceReplacements(changeSet);
   diff.resources.forEachDifference((logicalId: string, change: types.ResourceDifference) => {
     change.forEachDifference((type: 'Property' | 'Other', name: string, value: types.Difference<any> | types.PropertyDifference<any>) => {
@@ -246,10 +254,13 @@ function filterFalsePositivies(diff: types.TemplateDiff, changeSet: CloudFormati
   });
 }
 
-function findResourceReplacements(changeSet: CloudFormation.DescribeChangeSetOutput): types.ResourceReplacements {
-  const replacements: types.ResourceReplacements = {};
+function findResourceReplacements(changeSet: NestedChangeSet, replacements: types.ResourceReplacements = {}): types.ResourceReplacements {
   for (const resourceChange of changeSet.Changes ?? []) {
     const propertiesReplaced: { [propName: string]: types.ChangeSetReplacement } = {};
+    if (resourceChange.ResourceChange?.NestedChanges) {
+      // eslint-disable-next-line max-len
+      findResourceReplacements(resourceChange.ResourceChange.NestedChanges, replacements[resourceChange.ResourceChange!.LogicalResourceId!] as types.ResourceReplacements);
+    }
     for (const propertyChange of resourceChange.ResourceChange?.Details ?? []) {
       if (propertyChange.Target?.Attribute === 'Properties') {
         const requiresReplacement = propertyChange.Target.RequiresRecreation === 'Always';
diff --git a/packages/@aws-cdk/cloudformation-diff/lib/diff/types.ts b/packages/@aws-cdk/cloudformation-diff/lib/diff/types.ts
index e85265bf99c1f..134c107583148 100644
--- a/packages/@aws-cdk/cloudformation-diff/lib/diff/types.ts
+++ b/packages/@aws-cdk/cloudformation-diff/lib/diff/types.ts
@@ -6,7 +6,7 @@ import { SecurityGroupChanges } from '../network/security-group-changes';
 
 export type PropertyMap = {[key: string]: any };
 
-export type ResourceReplacements = { [logicalId: string]: ResourceReplacement };
+export type ResourceReplacements = { [logicalId: string]: ResourceReplacement | ResourceReplacements };
 
 export interface ResourceReplacement {
   resourceReplaced: boolean,
diff --git a/packages/aws-cdk/lib/api/nested-stack-helpers.ts b/packages/aws-cdk/lib/api/nested-stack-helpers.ts
index 26d0086d859c9..a2b01d9cd067a 100644
--- a/packages/aws-cdk/lib/api/nested-stack-helpers.ts
+++ b/packages/aws-cdk/lib/api/nested-stack-helpers.ts
@@ -1,4 +1,5 @@
 import * as path from 'path';
+import { NestedChangeSet } from '@aws-cdk/cloudformation-diff';
 import * as cxapi from '@aws-cdk/cx-api';
 import { CloudFormation } from 'aws-sdk';
 import * as fs from 'fs-extra';
@@ -21,14 +22,6 @@ export interface TemplateWithNestedStackCount {
   readonly nestedStackCount: number;
 }
 
-export type NestedChangeSet = CloudFormation.DescribeChangeSetOutput & {
-  Changes?: CloudFormation.Changes & {
-    ResourceChange?: {
-      NestedChanges?: CloudFormation.DescribeChangeSetOutput | NestedChangeSet,
-    },
-  }[],
-};
-
 /**
  * Reads the currently deployed template from CloudFormation and adds a
  * property, `NestedTemplate`, to any nested stacks that appear in either
diff --git a/packages/aws-cdk/lib/cdk-toolkit.ts b/packages/aws-cdk/lib/cdk-toolkit.ts
index 6ae81e0f3c3d8..f336658c6a4e2 100644
--- a/packages/aws-cdk/lib/cdk-toolkit.ts
+++ b/packages/aws-cdk/lib/cdk-toolkit.ts
@@ -203,7 +203,6 @@ export class CdkToolkit {
         const templateWithNames = await this.props.deployments.readCurrentTemplateWithNestedStacks(
           stack, options.compareAgainstProcessedTemplate,
         );
-
         const currentTemplate = templateWithNames.deployedTemplate;
         const nestedStackCount = templateWithNames.nestedStackCount;